Hello, I am refining a structure using a.eff file that I generated in Phenix version 1.7 GUI and later ran in the command line. When I try to run the same refinement in Phenix V.1.8 I get the following error: For French and Wilson scaling, sigma_iobs_rejection_criterion must be set between -4.0 and -1.0 I see that it was set to zero previously. My questions are: 1. Is this the same observed criterion that is reported in the RCSB Deposition? 2. To be honest I don't understand what this is. Is it a limit for the error in Iobs, below which the reflection will be discarded? 3. What is a reasonable setting for this input and how does it change the refinement? Thank you (I appreciate your help as I know these may be very basic questions). -Yarrow -- Yarrow Madrona Graduate Student Molecular Biology and Biochemistry Dept. University of California, Irvine Natural Sciences I, Rm 2403 Irvine, CA 92697